OBJECTIVES: a. The overall objectives of the total project is to survey a number of monooxygenase activities and characterize the effect that animal pretreatment or various monooxygenase inhibitors have on these enzyme systems. Lung cell isolation procedures will be established and after cells can be prepared in viable state, separation and characterization of cell types will be attempted. Lung perfusion experiments will be performed to compare cell and whole organ metabolism. b. The goals for the current year have focused on the survey of substrates for the lung monooxygenases which are well metabolized and on noting the effects of animal pretreatment of monooxygenase inhibitors on these activities.